Stress hyperglycaemia ratio and post-operative delirium after cardiac surgery: a retrospective cohort study of the MIMIC-IV database.

Delirium incidence was significantly higher in the high-ratio group than in the low-ratio group (18% vs 11%; P < 0.001).

A high ratio independently predicted delirium (hazard ratio, 1.54; 95% confidence interval, 1.31-1.82), with restricted cubic splines confirming a linear dose-response relationship (P for non-linearity = 0.203).

The support vector machine model achieved the best discriminative performance (area under the curve = 0.8042).